US 7183928 B2
A thermal imaging paper having a laminate structure is disclosed. The laminate structure includes a thermal imaging heat sensitive substrate, an adhesive layer, and a polyfoam layer. In addition, a security feature such as an antenna and integrated circuit are provided in a position interposed between said adhesive layer and said thermal imaging heat sensitive substrate. The thermal imaging paper provides the combination of an effective thermal imaging paper product incorporating the benefits of a security feature such as a wireless memory device.
1. A method of producing a thermal printed paper product incorporating a security feature from a thermal imaging system including a thermal printing device; a heat sensitive, thermal imaging paper, said thermal imaging paper having a laminate structure including a thermal imaging paper substrate having a first surface and a second surface, said first surface being positioned to face toward said thermal printing device during a printing process, a cushioning layer, a wireless memory device capable of reflecting RE signals, said cushioning layer and said wireless memory device being disposed along said second surface of the thermal imaging paper_substrate, and an adhesive layer, said wireless memory device being positioned between said thermal imaging paper substrate and said adhesive layer; and a detection unit, said detection unit being positioned in the proximity of said wireless memory device to transmit and receive RF signals from said wireless memory device, said method comprising the steps of:
thermally printing said thermal imaging paper with said thermal printing device; and
producing the thermal imaged paper product having said security feature, wherein said security feature includes said wireless device and said thermal imaged paper product includes at least one of a paper sheet, a roll of paper product, a label, and a tag.
2. A thermal printed paper product having a security feature produced by the process described in
This application is a continuation of U.S. application No. 10/183,511 filed on Jun. 28, 2002, Pat. No. 6,937,153. The entirety of the above-identified application is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a thermal imaging paper and a method of making a thermal imaging paper. In particular, the present invention relates to an thermal imaging laminate structure that includes a thermal imaging layer, an integrated circuit and antenna device, and a cushioning layer.
2. Description of the Background Art
Memory tags or labels for storing and retrieving data in the background art often employ a laminated circuit substrate positioned between a face sheet and a release liner. The memory devices for storing and retrieving data are well known in the related art, and include radio frequency (“RF”) tags that are readily available from a number of commercial manufacturers, including Texas Instruments and Phillips.
The face sheet provides a protective layer over one surface of the circuit substrate, thereby protecting the antenna and the electronic structure. A pressure sensitive adhesive may cover a second surface of the circuit substrate to readily affix the memory device to an item or container. The release liner provides a selectively removable layer over the pressure sensitive adhesive, which a user removes before applying the memory tag to an item or container.
The memory device of the background art may include a circuit substrate having an electronic structure such as an integrated circuit, and electrical connections such as traces and pads. For RF tag memory devices, an antenna is coupled to one or more pads of the circuit substrate. The electronic structure typically includes a memory portion and a logic portion. The logic portion controls the reading, writing, or manipulating of data in the memory portion. The logic portion further couples the memory portion to the antenna to form a transmitter, receiver, or transceiver for reading or writing data to or from the RF tag. Thus, for example, an RF tag may receive and transmit RF signals to write data to the memory and to read data from the memory.
U.S. Pat. No. 6,147,604 to Wiklof et al., the entire contents of which are hereby incorporated by reference, further describes the background art relating to wireless memory devices having a circuit substrate positioned within a laminate structure. The device described in the Wiklof et al. patent specifically provides a memory device having a substrate, an antenna formed on a first surface of the substrate, an electronic structure carried by the substrate and coupled to the antenna, a selectively deformable intermediate layer covering the first surface, the antenna and the electronic structure, and an adhesive layer covering the intermediate layer. In addition, the wireless memory device of the Wiklof et al. patent describes the use of a substrate, e.g., a flexible sheet type material having very low conductivity and preferably heat-resistant such as sheet plastic. The intermediate layer may take the form of a foam material, a selectively pressurizable and deformable envelope or other elastomeric material.
The intermediate layer is deformable for selectively positioning the antenna with respect to the adhesive layer, and thereby positioning the antenna with respect to an item or container to which the memory device is secured. The intermediate layer may be compressed, creating a relatively low profile for permitting printing on the memory device. In use, the intermediate layer may be in an uncompressed state, thereby spacing the antenna relatively from the adhesive layer and consequently spacing the antenna from the item or package to which the memory device is secured.
The device of the Wiklof et al. patent is aimed at specifically overcoming a prior art problem relating to the positioning of the wireless memory device's electrical components. If the antenna in an RF tag is too close to the device to which it is installed, unfavorable interference with wireless communications may be experienced, especially when the underlying container is made of metal.
With improvements in wireless memory devices, the necessity of providing a selectively deformable intermediate layer in a laminate structure is not essential for all applications. In addition, the present inventor has determined that the a thermal imaging laminate structure having a memory device and not requiring a selectively deformable intermediate layer can be cost effectively and advantageously employed in a variety of thermal imaging applications. In contrast to the heat resistant substrate of the background art devices such as that described in the Wiklof et al. patent, the present inventor has determined that a heat activated layer can be effectively utilized in conjunction with thermal imaging applications.
The present invention overcomes the shortcomings associated with the devices and methods of the background art, and achieves other advantages not realized by the background art.
It is an aspect of the present invention to provide a method and apparatus for a thermal imaging laminate structure having a wireless memory device for thermal imaging applications.
One or more of the aspects of the present invention are accomplished by a thermal imaging laminate structure comprising a thermal imaging paper substrate; a foam layer; a wireless memory device, the foam layer and the wireless memory device being disposed along the thermal imaging paper substrate; and an adhesive layer, the wireless memory device being positioned between the thermal imaging paper substrate and the adhesive layer.
One or more of these aspects of the present invention are also accomplished by a thermal imaging system comprising a thermal printing device;
One or more of these aspects of the present invention are also accomplished by a thermal imaging laminate structure comprising a thermal imaging paper substrate; a cushioning layer; a wireless memory device, the cushioning layer and the wireless memory device being disposed along the thermal imaging paper substrate; an antistatic coating layer; and an adhesive layer, the wireless memory device being positioned between the thermal imaging paper substrate and the adhesive layer.
One or more of these aspects of the present invention are also accomplished by a RFID product having a thermal imaging laminate structure, the product comprising a thermal imaging paper substrate; a cushioning layer; a wireless memory device, the cushioning layer and the wireless memory device being disposed along the thermal imaging paper substrate; an antistatic coating layer; and an adhesive layer, the wireless memory device being positioned between the thermal imaging paper substrate and the adhesive layer, wherein the product is at least one of a direct thermal label, a thermal transfer label, a direct thermal tag and a thermal transfer thermal tag.
One or more of these aspects of the present invention are also accomplished by a method of producing a thermal printed paper product incorporating the laminate structures and/or system described hereinabove, the method comprising the steps of thermally printing the thermal imaging paper with the thermal printing device; and producing the thermal imaged paper product having the security feature, wherein the security feature includes the wireless device and the thermal imaged paper product includes at least one of a paper sheet, a roll of paper product, a label, and a tag.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
The present invention will be described in greater detail hereinafter with reference to the accompanying drawings.
The present invention is directed toward a thermal imaging laminate structure, RFID product, a method of making the laminate structure, and a system employing the thermal imaging laminate with a security or wireless memory device. The thermal imaging laminate structure of the present invention is directed at a laminate structure that includes a thermal imaging heat sensitive layer 40, e.g., thermal papers such as OPTIMA® offered commercially through Appleton Papers. Thermal papers are increasingly used as facsimile paper, point of transaction, automated teller (ATM), pay-at-pump gas receipts and thermal label products, e.g., products sold to companies who apply pressure sensitive coating(s) and then distribute to label manufacturers. Thermal tag, ticket and chart grades of thermal papers are especially useful in specialty printing applications for conversion to finished products such as entertainment tickets, tags, coupons and medical charts.
Direct thermal and thermal transfer radio frequency identification (RFID) tags and labels are widely used in retail, inventory, security and other applications. The current construction of direct thermal and thermal transfer RFID tags and labels consists of a multi-layered laminate of a direct thermal imaging substrate made of paper, plastic or other material. Alternatively, a thermal transfer imaging substrate made of paper, plastic or other material as the first layer; an inlay which is an RFID circuit consisting of an integrated chip (IC), an antenna and an interposer to connect the chip to the antenna all mounted by adhesive onto a second substrate consisting of paper, plastic or other material as the second layer; a pressure sensitive adhesive or other adhesive device as the third layer; and a release liner as the fourth layer which can be peeled off the label leaving the glue or adhesive bare so that the tag or label can be affixed to the target application.
Direct thermal printing systems in general utilize a printing system where dots are selectively heated and cooled and dragged upon a heat-sensitive paper or substrate. The paper will turn dark in the areas specifically or selectively heated with precise measurements of heat by the thermal printing process and imaging device. A thermographic paper includes a label paper having a heat-activated coating that will accept an image from a thermal print head. Direct thermal papers are manufactured by coating papers with a special mixture of colorless dye, co-reactants and binders. When paper feeds through a thermal printer, heat from a thermal printer head causes dyes and co-reactants to activate and form an image. The image is created solely with a heated print head and the receiving medium, e.g. thermal paper.
Direct thermal paper products provide superior image quality, background whiteness and clarity, print contrast and character definition for direct thermal printing tasks, e.g. such as with OPTIMA® Thermal Paper products, and fast, reliable print operation. The quality and characteristics of the base paper and/or the application of the thermal coatings and their respective formulations is often performed with fully automated or computerized processes. Direct thermal papers can also be press printed, with flexographic, UV lithography and wet offset printing methods.
U.S. Pat. No. 5,821,196, the entirety of which is hereby incorporated by reference, discusses exemplary thermally-responsive record materials that are applicable to the thermal imaging technology of the present invention. Additional examples of other thermally-responsive record materials and systems well known in the art are further discussed in U.S. Pat. Nos. 3,539,375; 3,674,535; 3,746,675; 4,151,748; 4,181,771; 4,246,318; and 4,470,057, the entirety of each of which are hereby incorporated by reference.
Another form of thermal printing process involves a system referred to as thermal transfer. Thermal transfer printing systems operate similarly to direct thermal printing systems, with the exception that a single-use or intermediate ribbon is used and common paper is used as a substrate. Thermal transfer systems are often used in applications where problems of fading and/or changing colors would otherwise be problematic, such as in some direct thermal systems. However, thermal transfer systems do require the use of the ribbon material that involves a waste and/or recycling problem.
The thermal imaging laminate structure 100 of the present invention specifically incorporates any of the aforementioned thermal printing substrates, e.g. direct thermal, thermographic, thermal transfer paper, etc., as a thermal printing heat sensitive layer 40 within the laminate structure 100. One of skill in the art of thermal papers will appreciate that the actual makeup of the thermal printing heating sensitive layer 40 will vary according to the type of base paper, thermal coatings and end use that the thermal laminate structure 100 is intended to be applied and the particular thermal printing process of the laminate 100. In addition, the thermal printing heat sensitive layer 40 may be formed from a plurality of layers or from a single commercially available substrate, e.g. a roll of material selectively cut during the process of forming the laminate structure of the present invention.
The antenna 35 and microchip or integrated circuit 30, (referred to hereinafter collectively as a “wireless memory device”) would reflect radio signals to a detection unit (not shown) held or positioned in proximity to the thermal imaging laminate structure 100. As seen in
The integrated circuit 30 and antenna 35 are provided with the needed protection from physical damage and static electric discharge that is absent in the current products in the market. A flat printing surface for direct thermal and thermal transfer alpha numeric printing by eliminating the bump (as shown in
The cushioning layer 20 absorbs the extra thickness of the integrated circuit assembly (30, 32, 35) and keeps it from creating the convex surface protrusion as shown in
Static electricity protection is accomplished with the addition of the antistatic coating(s) 50 (shown in
An alternative way of providing antistatic properties to the direct thermal RFID or thermal transfer RFID label or tag, is the inclusion of antistatic materials directly in the manufacture of the cushioning layer 20 described hereinabove. Most of these antistatic treatments are proprietary to the commercial manufacturer of the cushioning material used and can be selected when selecting the cushioning material. Cushioning materials having antistatic properties specifically for the protection of the inlay circuits 30, 32, 35 and components described above in RFID direct thermal or thermal transfer tags and labels may include a combination(s) of antistatic coating(s) from the family of quaternary ammonium salts, sodium chloride, potassium chloride, conductive polymers, doped polyanilides, powdered metal coatings, or their equivalents and any of the aforementioned suitable materials for the cushioning layer 20.
The direct thermal RFID label or tag and the thermal transfer RFID label or tag of the present invention has the static dissipating ability to dissipate to 10% of full charge, a static charge of 5000 volts in less than 2 seconds after being conditioned in 20% relative humidity and 27 degrees centigrade for 24 hours. A design without the antistatic coatings of the claimed invention, conditioned under 20% relative humidity and 27 degrees centigrade for 24 hours, dissipated 5000 volts to 10% of full charge in greater than 12 seconds.
In the example shown in
A suitable pressure sensitive adhesive for the adhesive layer 10 is any acrylic pressure sensitive adhesive commonly used with a release liner 15. One of skill in the art will also appreciate that the pressure sensitive adhesive layer 20 can easily be replaced by other adhesives commonly available in the related art of adhesives, including but not limited to encapsulated adhesives that do not necessarily require a release liner 15 layer to protect the adhesive layer 10 during ordinary handling prior to installation or application. Instead, the use of an encapsulated adhesive permits the activation of the adhesive by a user or mechanical applicator through a preset or minimum pressure that would typically exceed pressures experienced during the ordinary handling of the laminate 100.
The cushioning layer 20 is a polyfoam layer 20 in a preferred embodiment. The cushioning layer 20 provides an intermediate layer between the adhesive and the wireless memory device 30, 35 that presents a smooth printing or application surface in contact with the thermal imaging heat sensitive layer 40. The relative resiliency of the polyfoam layer 20 permits the laminate 100 to conform to the shape of the wireless memory device 30, 35 and prevents errors in printing that might otherwise occur if the polyfoam layer 20 was not utilized, e.g. the printer head may skip over uneven portions of the thermal imaging heat sensitive layer 40 not corrected by the polyfoam layer 20.
One of skill in the art will appreciate that the polyfoam can be any of a variety of open or closed cell polyfoams, including but not limited to foam materials such as polyethylene, ethylene vinyl acetate, urethane, polyester, polyether, latex, silicone, urethane ethers, polypropylene, neoprene and poly-vinyl chloride. It will be appreciated that the flatness profile of the thermal imaging heat sensitive layer 40 will be optimized by the selection of a suitably resilient foam and a wireless memory device 30, 35 with a relatively flat and/or thin profile.
As aforementioned, the thermal imaging heat sensitive layer 40 can be any thermal paper and/or thermally coated substrate optimized for thermal printing processes such as direct thermal and thermal transfer printing processes, including but not limited to those examples further described in each of the U.S. patents incorporated by reference hereinabove.
The antistatic coating layer 50 can also be substituted or complemented with a protective topcoat or print receiving layer 50 designed to maintain the integrity of the thermal imaging heat sensitive layer 40, including but not limited to common topcoat or print receiving layers 50 made from polyvinyl alcohol.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.